We are about to have our loft insulated. It has been done before, but apparently it's not thick enough! We currently have the loft boarded, but due to the thickess of the new insulation, we won't be able to re-board. Does anyone have a solution, as we really need the storage space? Thanks.
Not sure I know what you mean? If we put joists at right angles to the ones we have, surely they will 'flatten' the insulation, which is what we are trying to avoid? Sorry if I misunderstand you!
You will probably have 3" joists with insulation of a similar depth laid between. If you cross-batten ( cross-joist, really) using joists to about the same depth as your required insulation and roll the insulation between these over the top of the existing insulation, you will have a 2-layer insulatory sandwich....
Kathy, what Jack means is fill the extra insulation between the added joists, on top of the boarding. Then new boards over that.
I've done just that a few times.
A possible alternative would be to not use "Loftroll" at all, but use a board such as Celotex of Kingspan. You could then put a "floating" floor right over the boards. No need for extra joists.
We are having it done through a council scheme (free!) The original insulation was already in when we bought the house 11 years ago. According to the guy who came round to see us, the insulation we have now doesn't come up to standard!
In a new build, the 'standard' depth for loft insulation is 270mm..........however, that assumes that is it also generic mineral-wool/glass-fibre quilting.
There are many products on the market with will provide the same insulatory qualities but are far thinner..............also far more expensive, too.